Casting wheel

ABSTRACT

A casting wheel ( 10 ) for use in filling ingot molds ( 36 ) of an ingot mold line has a wheel member ( 12 ) comprising a hub ( 14 ) and a plurality of spouts ( 20 ). The wheel member ( 12 ) has a central region ( 18 ) and is mounted by the hub ( 14 ) for rotation on an axis of rotation. The spouts ( 20 ) are formed from sheet metal and are integral with the hub ( 14 ). The spouts ( 20 ) extend outwardly from the central region ( 18 ) in an angularly spaced array and each spout has an inlet end ( 23 ) adjacent the central region ( 18 ) and an outlet end ( 24 ) remote from the hub ( 14 ). The casting wheel ( 10 ) additionally comprises means for mounting the wheel member for rotation on the axis of rotation, a conveyor ( 34 ) on which a series of ingot molds ( 36 ) are movable below the wheel member ( 12 ) along a mold line ( 36 ) extending transversely with respect to the axis, means for rotating the wheel member ( 12 ), means for advancing the conveyor ( 34 ) to move each mold ( 36 ) in turn to a filling position below a pouring position for spouts ( 20 ) of the wheel member ( 12 ), and molten metal feed means for supplying molten metal to the wheel member ( 12 ). The means for rotating the wheel member ( 12 ) and the means for advancing the conveyor ( 34 ) are operable in synchronism.

FIELD OF THE INVENTION

The present invention relates to casting wheels for use in filling ingotmoulds in automatic metal ingot moulding lines, and to a wheel memberfor such a casting wheel.

BACKGROUND TO THE INVENTION

Casting wheels (or rotating launders) are commonly used in the aluminiumindustry. Casting wheels have also occasionally been used for thecasting of ingots of other metals.

The general construction of a casting wheel includes a number of spouts(sometimes referred to as buckets) positioned on the perimeter of awheel which is designed to rotate about its axis. The casting wheel isusually indexed to a substantially flat conveyor which includes a numberof ingot moulds. The number and positioning of the spouts on the castingwheel is indexed such that each spout corresponds to one mould andallows for the filling of the mould with molten metal from the spout.

The general objective of all casting wheels is to provide an apparatusto prepare ingots of substantially equal size and weight which are freefrom scum and dross.

Problems associated with known casting wheels include the formation ofblockages in the pouring spouts; poor design of the spouts such that themolten metal experiences excessive turbulence when poured into the mouldand results in excessive dross; complex construction; and difficulty ofcleaning and maintenance.

Consistent ingot weight is only achieved if spout blockages do notoccur. Such blockages occur due to either oxide or dross formation.Dross formation would appear to be worse in the case of metals such asmagnesium than for aluminium, although some inconsistency in operationdoes occur with current aluminium casting wheels.

The turbulence issue is a function of the casting wheel design, the waymetal is added into the casting wheel and the location of the spout tipsin relation to the height of metal in the ingot mould. Most aluminiumcasting wheels are of a squat cylindrical design and run with a pool ofmetal in an open main trough or launder. When this pool encounters aspout, metal flows into the spout and then into the mould, hopefully insuch a way as the top surface skin of the metal in the pool is notdisturbed. In practice, this usually means pouring more than one mouldat a time. This can cause metal to flow into the mould when the spouttip is 5-10 cm above the mould bottom, causing splash and drossing.

In addition, the method of construction of the casting wheel needs to beaddressed. They are usually cast from steel or iron or are fabricatedfrom heavy gauge steel and are provided with some form of mould wash orcoating. If the thermal mass of the casting wheel is too large,extensive heating of it is required to prevent freezing of the metal inthe casting wheel. Known cast wheels need to have thick sections toenable them to be cast successfully. Cast wheels are normally limitedproduction items of complex design and so the casting costs are usuallyhigh.

Further problems are observed if casting wheels are used for castingmetals such as magnesium where the metal is cast under an inert orprotective gas as gas heating cannot be used.

At least in preferred forms, the present invention is concerned withcasting wheels, and wheel members for such wheels, which are suitablefor casting magnesium or magnesium alloys.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a wheel member, for acasting wheel for use in filling ingot moulds of an ingot mould line,the wheel member comprising:

a hub by which the wheel member is arranged to be mounted for rotationon an axis of rotation and which defines a central region; and

a plurality of spouts formed from sheet metal which are integral withthe hub and extend outwardly from the central region in an angularlyspaced array, each spout having an inlet end adjacent the central regionand an outlet end remote from the hub.

Preferably, the wheel member is formed from metal components which aresecured together to provide an integral rigid structure. This enablesthe wheel member to be readily designed for a specific installation.Preferably, the metal components are welded together. The spouts areformed from sheet metal and, to enhance rigidity, the hub is typicallyformed from relatively thin metal plate, for example, in the order of 10mm thick plate. The sheet metal from which the spouts are formed can beof relatively thin thickness, such as from about 1.5 mm to 4 mm thick,for example, about 2 mm thick. The sheet metal is preferably of lowthermal mass. For example, the spouts may be formed from steel, titaniumor a titanium alloy such as palladium stabilised titanium. The wheelmember may therefore have a low thermal mass which obviates the need forheating other than by molten metal being cast in order to preventfreezing of the molten metal. Additionally, the inside of the spouts maybe coated with a heat insulating material to reduce heat transfer to thespouts from molten metal flowing through the spouts. For example, theinside of the spouts may be plasma sprayed with alumina.

The wheel member may be of either of two distinct forms. In a first ofthese forms, the spouts are of open channel form in which molten metalflowing from the inlet to the outlet of successive spouts, in turn, isfully exposed to the surrounding atmosphere which, depending upon themetal being cast, may be an inert or protective atmosphere. In the otherdistinct form, each spout is of closed channel form between its inletand outlet ends and, in that case, the outlet end typically is submergedin molten metal of a mould being filled.

In a first preferred embodiment, the wheel member principally isintended to be mounted for rotation about a substantially horizontalaxis of rotation, and is rotatable so that each spout in turn moves to amelt pouring position in which it projects downwardly and forwardly fromthe hub. The spouts diverge outwardly and forwardly from the hub in afrusto-conical array, at a half cone-angle which is such as to ensurethat each spout, when in the pouring position, is inclined downwardlyand forwardly at an angle providing required, controlled flow of themelt.

In a second preferred embodiment, the axis of rotation preferably isinclined to the horizontal at an acute angle with the spouts generallyperpendicular to that axis, such that each spout is inclined downwardlyand forwardly when in the pouring position at an angle providingcontrolled flow of the melt.

It is to be understood that the first and second embodiments areopposite extremes. Thus, in a third preferred embodiment, each spout maybe at a required angle providing controlled flow of the melt as aconsequence of the spouts diverging at a greater half cone-angle thanfor the first embodiment, but with the axis of rotation being at alesser angle to the horizontal than in the second case embodiment.

In each of the first, second and third embodiments, the arrangementpreferably is such that each spout has a longitudinal centre-line whichis in a respective radial plane of the wheel member which contains theaxis of rotation. For a spout in the pouring position, such plane mostpreferably is substantially vertical. The inclination of the axis ofrotation and of the spouts preferably is such that a spout, when in thepouring position, is inclined downwardly and forwardly from the hub atan angle of from about 25° to about 45° to the vertical, such as at anangle of about 30° to the vertical.

The spouts of the first, second and third embodiments may be of open,channel form. A variety of cross-sectional configurations are suitablefor this, for example, V-section. In any event, it is desirable that, incross-section, opposite side walls of each spout are inclined downwardlyand inwardly towards each other. Most preferably the outer end of eachspout has a transverse end wall over which molten metal issues as a thincurtain when the spout is in its pouring position. Such end wall, whenits spout is in that position, most preferably is inclined downwardlyand forwardly at a relatively shallow angle with respect to thehorizontal, such as at an angle of from 5° to 25°, for example at about20° to the horizontal. However, the end wall may be horizontal.

In a fourth preferred embodiment of the wheel member according to thepresent invention, each spout curves outwardly and forwardly from thehub and has the form of a forwardly open scoop. In the fourthembodiment, each spout has an arcuate centre region along which moltenmetal is able to flow from its inlet end to its outlet end. The centreregion may be defined by an arcuate junction between respective mutuallyinclined side walls of its spout. However, it is preferred that thecentre region is defined by an arcuate basal wall which joins respectiveside walls of its spout.

In a fifth preferred embodiment of the wheel member, principallyintended for submerged filling of moulds, each spout is of closedchannel form between its inlet and outlet ends. From the inlet end tothe outlet end, each spout has a front wall along which molten metal isable to flow for discharge from an outlet defined at the outlet end,preferably to provide for submerged filling of moulds. Each front wall,at the inlet end of its spout, is spaced forwardly from the hub and isinclined so as to extend outwardly and rearwardly towards a planecontaining the hub. Each spout also has respective side walls and a rearwall, so as to be of rectangular form in cross-section where each wallis substantially planar. However, the front wall may be internallyconcave in cross-section so as to merge with each side wall, to giveeach spout a D-shape in cross-section.

In a sixth preferred embodiment, the arrangement is similar to that ofthe fifth embodiment. However, in the sixth embodiment which also isintended for submerged filling of moulds, each spout has a rear wallalong which molten metal is able to flow to an outlet defined at theoutlet end. Such rear wall, at the inlet end of its spout, extendsoutwardly and forwardly from the hub. Each spout has respective sidewalls and a front wall, so as to be of rectangular form in cross-sectionwhere each wall is planar. However, the rear wall may be internallyconcave, so as to merge with each side wall, to provide a D-shape incross-section.

Each of the fourth, fifth and sixth embodiments most conveniently isadapted for rotation on a substantially horizontal axis of rotation.However, each of these embodiments can be adapted for rotation on aninclined axis of rotation.

In each embodiment, successive spouts preferably are joined at theirinner ends along a forwardly extending junction between their side wallsor side wall portions. In each case, the arrangement preferably is suchthat each junction defines a relatively sharp divide between the inletend to successive spouts, which facilitates the diversion of moltenmetal from a spout leaving the pouring position to a spout at or closeto that position.

As indicated, the spouts are formed of metal sheet, such as mild steelor alloy steel. This enables attainment of the required rigidity at alesser wall thickness than is necessary for a wheel member cast of ironor steel, thereby saving in material and production costs. Also thethinner wall thickness possible with a wheel member having spoutsfabricated from sheet metal results in a reduction of heat loss from themolten metal to the wheel member, with a reduced risk of the moltenmetal solidifying and/or a reduced requirement for heating of the wheelmember to avoid solidification of the molten metal.

In a second aspect, the present invention provides a casting wheelcomprising a wheel member according to the first aspect of the presentinvention, means for mounting the wheel member for rotation on the axisof rotation, a conveyor on which a series of ingot moulds are movablebelow the wheel member along a mould line extending transversely withrespect to the axis, means for rotating the wheel member, means foradvancing the conveyor to move each mould in turn to a filling positionbelow a pouring position for spouts of the wheel member, and moltenmetal feed means for supplying molten metal to the wheel member, themeans for rotating the wheel member and the means for advancing theconveyor being operable in synchronism.

The means for rotating the wheel member and the means for advancing theconveyor are operable in synchronism. Preferably, the arrangement issuch that, as each mould approaches the filling position, it moves intovertical or near vertical alignment below the outlet end of a spoutwhich is approaching the pouring position. In further movement of themould, that outlet end enters the mould and is at a lowermost positionin the mould when the latter is at the filling position and the spout isat the pouring position. The lowermost position most preferably issufficiently close to the base of the mould as to substantially preventdross formation during the pouring of molten metal into the mould. Withstill further movement of the mould, the lower end of the spout iselevated within the mould during a filling operation and subsequently iselevated out of the mould, and the latter passes beyond the wheelmember. Simultaneously, next successive moulds are moved along the mouldline, each relative to a respective one of next successive spouts of thewheel member. Rotation of the wheel member and the conveyor may becontinuous. Alternatively, it may be in an intermittent, step-wisefashion.

The molten metal feed means may include an open launder or, for somemetals, a pipe, along which molten metal is conveyed to the wheel memberfrom a suitable source. The launder or pipe preferably has an outlet endadjacent to the central region of the hub of the wheel member, to enabledischarge of molten metal into the inlet end of a spout at the pouringposition. Alternatively, the molten metal feed means may comprise atundish.

The molten metal feed means may discharge molten metal at a locationclose to, but spaced from, the central region so as to pass directly tothe inlet end of a spout in the pouring position. That is, the flow ofmolten metal need not, and preferably does not, contact the centralregion. However, the central region may be of dished form andparticularly in such case, it may serve to guide molten metal in flowfrom the feed means to the inlet end of a spout in that position.

When rotation of the wheel member and drive to the conveyor isstep-wise, the wheel member and the conveyor is stopped as eachsuccessive spout and mould respectively reaches the pouring the fillingpositions. At least partial filling of the mould then is effected, ifnecessary with the supply of molten metal having been momentarilyterminated or reduced after completion of filling of the precedingmould. However, on commencement of filling of a mould at the fillingposition, rotation of the wheel member and drive to the conveyor againis initiated, such that completion of filling of the mould is achievedas it moves beyond the filling position. That is, filling of the mouldis asymmetric with respect to its movement to and beyond the fillingposition. Such asymmetric filling has the benefit of enabling the outletend of a spout to be elevated, relative to its mould, as a consequenceof rotation of the wheel member. This elevation may be such as tomaintain the outlet end of the spout a short distance above the risinglevel of molten metal in the mould or with the outlet end submerged andelevated with the rising level of molten metal in the mould. In eithercase, asymmetric filling preferably also is achieved when rotation ofthe wheel member and drive to the conveyor is continuous.

The molten metal feed means preferably is arranged relative to the wheelmember in a manner which facilitates attainment of such asymmetricfilling. There are two arrangements which achieve this, although theycan if required be used in combination.

In the first arrangement, the molten metal feed means has an outletwhich is laterally offset from the axis of rotation to that half of thewheel member to which a spout first rotates on leaving the pouringposition. As a consequence of this, the feed means outlet is able to beabove, and discharge molten metal to, the inlet end of a spout during atime and angular distance interval of movement of the inlet end of thespout beyond the pouring position. In the second arrangement, the moltenmetal feed means conveys the molten metal along a line, to its outlet,such that on issuing from the outlet, the molten metal has a downwardflow path having a lateral component of movement towards the half of thewheel member referred to above. Again, in the second arrangement, theoutlet of the feed means is able to discharge molten metal to the spoutmelt end over such time and distance interval.

The spouts preferably decrease in cross-section from the inlet end tothe outlet end. This most conveniently is as a consequence of mutuallyinclined side walls which, while at a constant angle to each other,decrease in height to the outlet end. Adjacent the hub, the side wallsof each spout may diverge towards the inlet end such that each side wallmerges with, and is joined to, an adjacent side wall of the nextadjacent spout. The junction between side walls of adjacent spoutspreferably projects forwardly from the hub, such as forwardly andoutwardly. The junctions may define a relatively sharp separationbetween the inlet end of successive spouts which facilitates thecutting-off of molten metal feed to one spout as the next followingspout approaches the pouring position.

Any suitable molten metal feed means may be used. The selection anddesign of the feed means will depend upon the type of molten metal andthe temperature thereof. For metals such as lead or magnesium the feedmeans preferably includes a pump and steel pipe.

The wheel member may have any suitable number of spouts. Factorsaffecting the choice of number of spouts include the size, weight andoverall cost of construction of the wheel. The number of spouts also canalter the production rate of ingots. Generally the greater the number ofspouts the greater the production rate. In a preferred embodiment thewheel member has from 6 to 12 spouts.

In a preferred embodiment of the invention each spout is designed suchthat the internal surfaces, along which molten metal is to flow, slopefrom the inlet end to the outlet end thereof. The surfaces may be flator curved. This design substantially reduces the risk of dead zones andminimises blockages due to dross formation or metal freezing and allowsfor the production of substantially consistent ingot weights. Thesloping surfaces also can minimise turbulence of the molten metal whenfilling an ingot mould, thereby minimising dross formation. Open spoutconstructions enable greater visibility of a casting operation,resulting in better control of the production of ingots, and allows foreasier cleaning and maintenance. However, closed spout constructions areable to be provided with a separable cover portion to facilitatecleaning and maintenance.

In a preferred embodiment of the invention each spout is designed suchthat all the internal surfaces, along which molten metals is to flow,slope from the inlet end to the outlet end. Such angular design of thespouts forms an inherently stiff structure making the use of heavy steelsections unnecessary. This results in a casting wheel of substantiallyless thermal mass than cast wheel members and is important for metalswith low heat capacity such as magnesium as it allows them to be castwith less possibility of freezing and causing blockages in the spouts.It also means that the cost associated with pre-heating buckets orspouts can be minimised.

Known casting wheels are designed and constructed such that their axisof rotation is in a substantially horizontal plane. However, the presentinvention enables a departure from this, in that it is possible to usethe casting wheel of at least some embodiments at an inclined axis. Thisarrangement can further minimise turbulence of the molten metal pouringinto the moulds.

BRIEF DESCRIPTION OF DRAWINGS

Preferred embodiments of the present invention will now be described, byway of example only, with reference to the accompanying drawings, inwhich:

FIG. 1 is a partial front elevation of one form of a casting wheel ofthe present invention;

FIG. 2 is a side elevation of the casting wheel as shown in FIG. 1;

FIG. 3 is a perspective view of a spout of a casting wheel of FIGS. 1and 2;

FIGS. 4a and 4 b are inverted plans of spouts similar to FIG. 3,

FIG. 5 is a schematic side elevation of an alternative form of wheelmember;

FIG. 6 is a partial perspective view of the wheel member of FIG. 5; and

FIGS. 7 and 8 correspond respectively to FIGS. 5 and 6, but show a stillfurther form of wheel member.

DETAILS DESCRIPTION OF DRAWINGS

Referring firstly to FIGS. 1 and 2 of the drawings, the casting wheel 10includes a wheel member 12 arranged for rotation about a horizontallydisposed axis X—X. Wheel member 12 has a central hub 14 by which it isrotatable with shaft 16 and which defines a central region 18. Wheelmember 12 is formed with eight spouts 20 a to 20 h (referred tocollectively as spouts 20).

Shaft 16 is journaled in bearings 17 (FIG. 2) and rotatable under theaction of suitable drive means 18. Across its forward end, shaft 16 hasan integral end plate 21, to which hub 14 is secured by bolts 22.

Referring to FIG. 3, each spout 20 is in the form of a closed truncatedrectangular based pyramid having an inlet end 23 and a circular outletend 24. As illustrated in FIGS. 4a and 4 b, the outlet end 24 may have avariety of shapes including elliptical and an elongated slot.

Wheel member 12 is formed principally of 2 mm thick steel sheetcomponents which are welded together; hub 14 comprising 10 mm circularplate for rigidity. Although made from relatively light steel sheet andplate, the construction has a high level of rigidity.

The casting wheel 10 also includes molten metal feed means 26, having asupply pipe 28 by which molten metal is able to be conveyed to the wheelmember 12 from a suitable source (not shown). Pipe 28 terminates,adjacent central region 18, at a down-turned discharge end 30. Thearrangement is such that pipe 28 is able to discharge molten metal fromits discharge end 30 for flow into the inlet end of a spout 20 when thelatter is at a pouring position vertically below axis X—X.

In the arrangement as shown in FIG. 1, the wheel member 12 is rotated byshaft 16 in an anti-clockwise direction. This brings each spout 20, inturn, to and then beyond the pouring position. The pouring position isoccupied by spout 20 a shown in FIG. 1. Pipe 28 is mounted so as tolocate its discharge end 30 asymmetrically with respect to axis X—X;discharge end 30 being laterally offset slightly to the half of thewheel member 12 to which each spout 20 rotates, in turn, on leaving thepouring position. Thus, flow of molten metal from discharge end 30 tothe inlet end 23 of a spout 20 commences a short interval before thespout reaches that position, and is terminated after a larger intervalof movement of the spout beyond that position.

The junction 32 between each pair of successive spouts 20 functions as amolten metal flow diverter. The junction 32 between the spout 20 a shownin the pouring position in FIG. 1 and preceding spout 20 h is in aposition in which the flow of molten metal is split between those spouts20 a and 20 h. Until a short interval prior to spout 20 a reaching thepouring position, all flow is to inlet 23 of spout 20 h. However, asspout 20 a approaches and then moves beyond the pouring position,junction 32 commences to divert an increasing proportion of the metalflow from spout 20 h to spout 20 a, until all flow is to spout 20 a.After a further interval, the adjacent junction comes into operation, todivert flow to spout 20 b.

The casting wheel 10 further includes a conveyor system 34 which has aseries of ingot moulds 36. System 34 is operable under the action ofdrive means (not shown) for moving moulds 36 along a mould lineextending below axis X—X. Each mould 36 is coupled to a respective chainor belt shown schematically at reference number 7 of system 34, by whichmoulds 36 are advanced along the mould line by an advancement meansshown schematically at reference number 38.

The drive for rotating wheel member 12 on axis X—X is synchronised withthe drive for moving moulds 36 along the mould line. The arrangement issuch that, as each of spouts 20 a to 20 h reaches the pouring positionshown for spout 20 a, a respective mould 36 reaches a filling position.Only three of moulds 36 of system 34 are illustrated in FIG. 1, withthese being distinguished as moulds 36 a, 36 b and 36 h to highlighttheir association with spouts 20 a, 20 b and 20 h, respectively. As willbe appreciated, mould 36 a is shown as being in the filling position.

The mould line is substantially perpendicular to axis X—X. The verticalspacing between the mould line and axis X—X, and the location of mouldline longitudinally of axis X—X is such as to provide a required workingrelationship between spouts 20 and moulds 36. This relationship, whichalso is dependent on the synchronism of rotation of wheel member 12 andmovement of moulds 36, brings the outlet end 24 of each of spouts 20into a required relationship with its respective mould 36.

As shown in FIG. 1, the outlet end 24 of spout 20 b is over and hascommenced entry to mould 36 b. Spout 20 a is in the pouring position,while mould 36 a is at the filling position, such that the outlet end 24b of spout 20 a is closely adjacent the base of mould 36 a. As junction32 between spouts 20 a and 20 h has commenced traversal across thedischarge end 30 of pipe 28, it has reached a position in which it hasbecome able to commence the diversion of flow of molten metal from inletend 23 of spout 20 h to the inlet end 23 of spout 20 a. Thus moltenmetal flowing from discharge end 30 to inlet end 23 of spout 20 a isable to flow through spout 20 a and discharge via its outlet end 24 intomould 36 a. Flow of molten metal through and discharge from a spout 20is illustrated in FIG. 3 and it is to be noted that the arrangementresults in flow of minimum turbulence. Also, the close positioning ofoutlet end 24 to the base of the mould 36 a further minimises turbulencewith consequential minimisation of the risk of dross formation.

The filling of mould 36 a continues as it advances beyond the fillingposition to a position just beyond that shown as occupied by mould 36 hin FIG. 1. During this, rotation of spout 20 a beyond the positionoccupied by spout 20 h, causes elevation of its outlet end 24. Thearrangement preferably is such as to achieve underpouring of the moulds36 a (ie. the outlet end 24 of spout 20 a remains close to, but justbelow, the rising level of molten metal in mould 36 a) this againminimising turbulence and the risk of dross formation. A position isreached in which junction 32 commences the diversion of flow from spout20 a to spout 20 b. This diversion is complete when mould 36 a is filledwith a required volume of metal, and the outlet end 24 of spout 20 a iselevated away from mould 36 a, and the mould 36 a advances beyond wheelmember 12.

FIGS. 1, 2 and 3 illustrate a casting wheel made and found to operateefficiently for casting of ingots of magnesium with negligible formationof oxide or dross and with an ingot mass deviation of 8.0 kg±0.1 kg.This casting, of course, necessitated operation under a protective gasatmosphere, as required for protection of a magnesium melt. Thesuitability of the casting wheel of the present invention for castingmagnesium reflects a significant departure from known casting wheelsused for casting aluminium ingots and procedures for casting magnesiumingots. The casting wheel of the present invention is relativelyinexpensive and enables heat loss from the molten metal to the wheelmember to be minimised, with avoidance of the need for external heatingof that member to offset heat loss. Also, the casting wheel is wellsuited to manufacture on a scale suitable for obtaining high volumecommercial production of ingots.

FIGS. 5 and 6 illustrate a wheel member 112 formed of sheet metalcomponents which are welded together. Member 112 has a central hub 116by which it is connected to and rotatable with horizontally disposedshaft 118, in the manner described with reference to wheel member 12 ofFIGS. 1 and 2. Member 112 further includes eight angularly disposedspouts 122 of which only part of the exterior of five is visible in FIG.5. Also, as with wheel member 12 of FIGS. 1 and 2, the forward face ofhub 116 defines a central region 120 which leads to the inlet end 123 a(see FIG. 4) of each spout 122.

As shown more clearly in FIG. 6, each spout 122 is in the form of aforwardly open scoop, and is defined by an arcuate centre wall 100 and apair of side walls 102. Each centre wall 100 is welded at inlet end 123a of its spout 122 around and to the periphery of hub 116. From hub 116,walls 102 curve arcuately outwardly and forwardly from inlet end 123 ato outlet end 123 b of the respective spouts 122. The resultantforwardly facing concave surface 100 a of each wall 100 defines a flowpath for molten metal during a mould filling operation. The width ofwall 100 a decreases from inlet end 123 a to outlet end 123 b, toprovide more positive channelling of metal flow to end 123 b.

Each side wall 102 has the form of a quarter of a circular disc. Alongits arcuate edge 102 a, each wall 102 is welded to a respective centrewall 100 of its spout so that one of its linear edges 102 b projectsforwardly from hub 116 and the other such edge 102 c upwardly fromoutlet end 123 b of its spout 122.

Successive spouts 122 are joined together by welding along adjacentedges 102 b. The resultant junction between edges 102 b is similar inform and function to junctions 32 of wheel member 12 of FIGS. 1 and 2.

Operation with wheel member 112 is similar to that described in relationto member 12 of FIGS. 1 and 2. As indicated in FIG. 5, member 112 isused in association with molten metal feed means 130, and also an ingotmould conveyor system (not shown).

FIGS. 7 and 8 show a wheel member 212, in which components correspondingto those of member 112 of FIGS. 5 and 6 have the same reference number,plus 100. Description principally will be limited to features by whichmember 212 differs from member 112.

In the arrangement of FIGS. 7 and 8, each spout 222 is closed betweenits inlet end 223 a and its outlet end 223 b. Also, each spout 222 is inthe form of a hopper of rectangular cross-section between its inlet end223 a and outlet end 223 b, with end 223 b defining an outlet 204 forthe discharge of molten metal. Each spout has a rear wall 200, sidewalls 202 and a front wall 205, each formed of flat metal plate andjoined to adjacent walls by welding. Each rear wall 200 is welded, atinlet end 223 a of its spout 222, around and to part of the periphery ofhub 216. From hub 216 walls 200 are inclined outwardly and forwardly,while each front wall 205 is substantially parallel to but forward ofhub 216, such that the respective outlets 204 are forwardly of hub 216.

Walls 200 and 205 of each spout 222 taper slightly from the inlet end223 a to its outlet 204, such that the side walls 202 diverge outwardlyfrom outlet 204 to inlet end 223 a. Also, adjacent walls 202 ofsuccessive spouts are joined at inlet ends 223 a, to define a respectivejunction 202 b which functions as for a junction 32 of member 12 ofFIGS. 1 and 2.

Again, operation with member 212 will be understood from description ofcasting wheel 10 of FIGS. 1 and 2. Also, molten metal feed means 230 (aswith means 130 of FIGS. 5 and 6) preferably is offset from the axis ofrotation in the manner described for means 26 of FIGS. 1 and 2, and forsimilar functioning.

With further reference to wheel member 112 of FIGS. 5 and 6, it will beappreciated that the curvature of the concave surface of each centrewall 100 controls turbulence in metal flow. The curvature may besmoothly uniform from the inlet end 123 a to the outlet end 123 b.However, the curvature may increase progressively and, if necessary toincrease the radial extent of each spout 122, each wall 100 may have asubstantially linear inner end portion which guides flow to an outerarcuate portion.

With further reference to FIGS. 7 and 8, it similarly will beappreciated that the inclination of rear walls 200 controls the flow ofmolten metal and enables turbulence to be minimised. Variation also ispossible in this embodiment, in that the orientation of each spout 222can be reversed. That is, the rear walls may be substantially parallelto and project radially from hub 216, with from the front walls beinginclined outwardly and rearwardly from its inlet 223 a to its outlet204. With such variation, it of course will be the front walls alongwhich molten metal will flow and by which its flow will be controlled.Also, in such variation, the outlet end of molten metal feed means 230will need to have its outlet end further from hub 216, for the dischargeof molten metal onto the end of the front wall adjacent the inlet end ofeach spout.

Finally, it is to be understood that various alterations, modificationsand/or additions may be introduced into the constructions andarrangements of parts previously described without departing from thespirit or ambit of the invention.

What is claimed is:
 1. A wheel member, for a casting wheel for use infilling ingot moulds of an ingot mould line, the wheel membercomprising: a hub by which the wheel member is arranged to be mountedfor rotation on an axis of rotation and which defines a central region;and a plurality of spouts formed from sheet metal which are integralwith the hub and extend outwardly from the central region in anangularly spaced array, each spout having an inlet end adjacent thecentral region and an outlet end remote from the hub.
 2. A wheel memberas claimed in claim 1 wherein the spouts are formed from steel sheethaving a thickness of 1.5 mm-4 mm.
 3. A wheel member as claimed in claim1 wherein the spouts are formed from titanium sheet or titanium alloysheet.
 4. A wheel member as claimed in claim 1 wherein the hub is formedfrom metal plate, the spouts are formed from a plurality of sheet metalcomponents, and the sheet metal components and the hub are securedtogether.
 5. A wheel member as claimed in claim 4 wherein the sheetmetal components and the hub are welded-together.
 6. A wheel member asclaimed in claim 1 wherein the inside of the spouts is coated with aheat insulating material.
 7. A wheel member as claimed in claim 1wherein each spout is of a closed channel form between its inlet end andits outlet end.
 8. A wheel member as claimed in claim 7 wherein eachspout decreases in cross-sectional area from its inlet end to its outletend.
 9. A wheel member as claimed in any claim 1 wherein each spout isof an open channel form.
 10. A wheel member as claimed in claim 1wherein the inlet ends of adjacent spouts meet at a junction.
 11. Awheel member as claimed in claim 1 wherein the axis of rotation ishorizontal.
 12. A wheel member as claimed in claim 1 in combination witha conveyor having a series of ingot moulds corresponding to respectivesaid spouts, said conveyor having a conveyor advancing means for movingthe ingot moulds along a mould line below the wheel member, which mouldline extends transversely with respect to the axis of rotation of thewheel member and wherein the conveyor moves each mould in turn to afilling position below a pouring position for spouts of the wheelmember, means for rotating the wheel member, said wheel member furtherincluding molten metal feed means for supplying molten metal to thewheel member, wherein the means for rotating the wheel member includessynchronizing means cooperable with the conveyor advancing means torotate the wheel member in synchronism with the conveyor advancingmeans.
 13. A wheel member as claimed in claim 12 having a diameter thatis selected to permit the outlet end of each said spout to be submergedin molten metal during filling of a mould that is positioned apredetermined distance from said axis of rotation.
 14. The wheel memberas claimed in claim 12 wherein the means for rotating the wheel memberinclude means for maintaining continuous rotation of the wheel member tocorrespond to continuous advancement of the conveyor.